A burnt car in front of US consulate, after an attack that killed four Americans, including Ambassador Chris Stevens. (AP)

Libyan authorities have made four arrests in the investigation into the attack on the US consulate in Benghazi where US ambassador and three embassy staff were killed as two of the four Americans killed in the assault on the U.S. Consulate in Benghazi were identified as former Navy SEALs.

A source confirmed to Fox News on Thursday that one of the victims was Tyrone Woods, a 41-year-old former SEAL.

Glen Doherty, a former Navy SEAL from Massachusetts, was also one of the victims of the deadly attack on the US Consulate in Benghazi, a family friend confirmed to Fox News.

Doherty is the latest victim to be identified. The US government earlier confirmed that US Ambassador to Libya Christopher Stevens and Sean Smith, a foreign service information management officer, died in the attack.

The name of the fourth American who died in the attack has not been disclosed.

Meanwhile, Libya’s deputy interior minister Wanis al-Sharef told Reuters, “Four men are in custody and we are interrogating them because they are suspected of helping instigate the events at the U.S. consulate.”

The Boston Globe first reported that Doherty was among the victims. His sister told the Globe that Doherty, 42, was working for a private company providing security at the time.

A former ski instructor in Utah, Doherty reportedly trained as a sniper and medical officer after joining the Navy SEALs.

He served for seven years before leaving to work at the private security firm.

Al-Sharef said earlier Thursday the Benghazi attack was an organized two-part operation by heavily armed militants.

The attack included a precisely timed raid on a supposedly secret safe house just as Libyan and US security forces were arriving to rescue evacuated consulate staff.

Al-Sharef said on Thursday the attacks were suspected to have been timed to mark the anniversary of the Sept. 11 attacks and that the militants used civilians protesting an anti-Islam film as cover for their action.